放牧对贝加尔针茅草原群落植物多样性和生产力的影响

研究了不同放牧强度对贝加尔针茅草原群落植物多样性和生产力的影响。结果表明,在牧压梯度上,不同的植物表现出不同的生态适应对策,贝加尔针茅种群随着牧压的增加,种群株丛破碎化、小型化,羊草耐牧性较强,在中牧阶段生产力最高。群落初级生产力随着放牧强度的增加逐渐下降。较大的放牧压力下,群落中适口性差、耐牧的杂类草植物渐趋增加。而在更大的放牧压力下,群落逐步被耐牧的小丛生禾草、旱生小苔草、小灌木和灌木所替代。草地群落的稳定性随着放牧强度增加逐渐降低。放牧干扰对群落植物多样性和生产力及其稳定性的影响是不同步的,不对称的。植物群落初级生产力对放牧干扰的响应更迅速,变化更剧烈。

Effects of grazing intensity on plant diversity and aboveground biomass of Stipa baicalensis grassland.

The study on the plant diversity and aboveground biomass of Stipa baicalensis grassland under different grazing intensity showed that with increasing intensity of grazing,the plant cluster of S.baicalensis population fragmented and miniaturized;while Leymus chinensis had stronger capability in enduring grazing,and its aboveground biomass was the highest under moderate grazing.The primary biomass of the grassland community decreased with increasing grazing intensity.Under higher grazing intensity,the weeds worse for feeding and with higher capability in enduring grazing increased.When the grazing intensity increased continuously,the population would be replaced by the weeds.The stability of the grassland population also decreased with increasing grazing intensity,but the effects on the population diversity,aboveground biomass,and stability were not synchronous and symmetry.There was a rapid and intensive response of the primary biomass of the grassland community to grazing disturbance.